Re: Why is the ocean blue?

Why is the ocean blue?

If the ocean is blue due to the reflection and refraction of the scattered blue light, why is that a large bowl of water kept outdoors does not appear blue ? Please dont tell me this true for only large masses of water or that our eyes and brain is not devoloped enough to perceive this !

Unfortunately for your qualifications, only a large amount of water -- or air, for that matter: why doesn't a bottle filled with air appear blue? -- will scatter enough light to appear blue.

A large bowl of water is just not deep enough to take on a profound blue color, because water is transparent and you end up seeing the bottom and sides of the bowl instead. While it is true that you can see a reflection at the proper angle (and if the sky is a brilliant blue, the reflection may well be blue), reflection of the sky is only part of the answer to why the ocean is blue. The rest has to do with light scattering.

Now, it is true that fine particles suspended in water (or air) aid the scattering process; but again, too high a density of fine particles and the fluid just looks murky (think of a dust storm!) rather than looking blue. You still need some depth of fluid to get a blue appearance. And a bowl of water, even a rather large bowl, just doesn't have the depth.

For that matter, most small lakes don't have enough depth to appear blue, either -- not to mention that most of them are pretty murky with fish stuff and freshwater plants. You have to go to a really deep lake, like Lake Superior or Lake Baikal, to get the profoundly blue appearance of the ocean.